Many thanks for your replies. to answer some questions
Tried access with Firefox and find no problem - IE still has problem
Windows up dates are all up to date - last one loaded yesterday
Using Avast but removed it yesterday and problem still with IE
Also turned off firewall - same problem
After further investigation I was able to access the Certification path and find that the problem sites
are:-
DST Root CAX3 - IdenTrustCommercial Root Ca 1 - TrustID Server CA A52 - letsencrypt .org
& DST Root CAX3 - Let’s Encrypt Authority X3 - www.beiley.com
When I highlight the DST Root CAX3 the certificate status box says - The CA Root certificate is not trusted because it is not in the Trusted Root Certificate Authorities store.
This would obviously seen to be the problem as when I check -Trusted Root Certification Authorities - certificates - I cannot find DST Root CAX3 mentioned.
My question now is how do I get DST Root CAX3 registered as a trusted Certificate - is it possible to copy the file from my Win 10 Machine to Win 7 machine - will it work or do I need a Win7 version.